Virtual image display device shifting light of an image to create a virtual image
AssigneeDenso Corporation
InventorsKazuhisa Onda, Hiroshi Ando
Life of this patent
Estimating the term…
Abstract
A light guide unit forms an optical path to guide a display light emitted from a display unit toward a projection portion. The light guide unit includes a negative optical element and a positive optical element. The negative optical element is placed on the optical path and has a negative optical power. The positive optical element is placed on the optical path and is closer to the projection portion than the negative optical element. The positive optical element has a positive optical power. The positive optical element is a diffractive optical element having a diffractive structure configured to diffract the display light.
Claims8
A virtual image display device configured to be mounted on a vehicle and to cause a projection portion to reflect a display light of an image to display the image as a virtual image to be visible, the virtual image display device comprising:
- a display configured to emit the display light;
- and
- a light guide unit configured to form an optical path to guide the display light emitted from the display toward the projection portion,
- wherein
- the light guide unit includes:
- a negative optical element placed on the optical path and having a negative optical power;
- and
- a positive optical element placed on the optical path and closer to the projection portion than the negative optical element, wherein
- the positive optical element has a positive optical power,
- the positive optical element is a diffractive optical element having a diffractive structure configured to diffract the display light, and
- the negative optical element is a diffractive optical element having a diffractive structure configured
- to cause a color shift in a direction opposite to a direction of a color shift caused by a chromatic aberration of magnification of the positive optical element and
- to diffract the display light.
A virtual image display device configured to be mounted on a vehicle and to cause a projection portion to reflect a display light of an image to display the image as a virtual image to be visible, the virtual image display device comprising:
- a display configured to emit the display light;
- a light guide unit configured to form an optical path to guide the display light emitted from the display toward the projection portion;
- and
- an absorber configured to absorb the display light,
- wherein
- the light guide unit includes:
- a negative optical element placed on the optical path and having a negative optical power;
- and
- a positive optical element placed on the optical path and closer to the projection portion than the negative optical element, wherein
- the positive optical element has a positive optical power,
- the positive optical element is a diffractive optical element having a diffractive structure configured to diffract the display light, and
- the positive optical element is configured
- to guide a primary light among the display light, which is incident on the positive optical element, toward the projection portion and
- to emit a zero-order light among the display light toward the absorber.
A virtual image display device configured to be mounted on a vehicle and to cause a projection portion to reflect a display light of an image to display the image as a virtual image to be visible, the virtual image display device comprising:
- a display configured to emit the display light;
- and
- a light guide unit configured to form an optical path to guide the display light emitted from the display toward the projection portion,
- wherein
- the light guide unit includes:
- a negative optical element placed on the optical path and having a negative optical power;
- and
- a positive optical element placed on the optical path and closer to the projection portion than the negative optical element, wherein
- the positive optical element has a positive optical power,
- the positive optical element is a diffractive optical element having a diffractive structure configured to diffract the display light, and
- the positive optical element is configured
- to guide a primary light among the display light, which is incident on the positive optical element, toward the projection portion and
- to emit a zero-order light among the display light in a direction toward an outside of the virtual image display device other than the projection portion and the visible region where the virtual image is visible.
Dependencies are inferred from the claim text.